1. Field of the Invention
This invention generally relates to the measurement of power consumption and more specifically to non-intrusive and self-powered measurement of electrical current flow through a power line to enable analysis of power consumption on a per circuit breaker basis.
2. Prior Art
In a typical electricity distribution system, power is provided through a main circuit breaker and a device for measurement of the power consumption of the entire electrical network connected thereto. However, typically, the main power line is then connected to a plurality of circuit breakers, each feeding a smaller section of the electrical network with its specific power requirements. The circuit breaker is adjusted to the amount of maximum current that may be used by this electrical sub-network. In industrial and commercial applications, hundreds of such circuit breakers may be installed, each controlling a section of the electrical network. Even in smaller locations, such as a house, it is not unusual to find tens of circuit breakers controlling various electrical sub-networks.
Non-intrusive measurement of current through a power line conductor has well known principles. A current transformer (CT) of sorts is created that comprises the primary winding as the power line conductor and the secondary providing an output current inversely proportionate to the number of windings. Typically such systems are used for measuring currents in very high voltage or current environments, for example, as shown in Gunn et al. in U.S. Pat. No. 7,557,563. These types of apertures are useful for main power supplies. Using such devices, or power meters for that matter, is deficient for the purposes of measuring relatively low currents in an environment of a plurality of circuit breakers. Providing wireless telemetry on a singular basis, such as suggested by Gunn et al., and other prior art solutions, suffers from deficiencies when operating in a noisy environment.
There is a need in the art that is now developing, resulting from the move toward energy conservation to enable analysis of power consumption on a finer granularity. This would require analysis on at least a per circuit breaker basis and such solutions are not available today. It would be further advantageous if a solution may be provided for installation in a circuit breaker closet for existing circuit breakers. It would be therefore beneficial to overcome the limitations of the prior art by resolving these deficiencies.